Fuse powder



May 16, 1933. A, HERST 1,908,979

4FUSE! -POWDER 'Filed Feb. 18, 1931 mlm Patented May 16, 1933 UNITED STATES- eminence a. HERBST, or omesso. ILLINOIS,.essieudiarioQiicoiioiitir;ausnutzen.lithium` nomine oo., or cmcaeo, 3ILLino1s, A coaroRnrIoir-or. New. Yonge A .2.

This invention relates to improvements in methods for manufacturin a fillerfor elec-' 4 trical fuses commonly calle a fuse owder.

of substantially uniform size.

' According to the ordinary practice it has been customary to add a certain percentage:

spray'fpipef 16 s serves -to admit ywfa'ter. so-tl'ifit -=tli material 'which is Achargedzinto-fthe:barrel .a tree :,piv'otjlSi ht E'the center. offrotation-o of water to calcium sulphate as a base malterial so that the material becomes caked. .1: The caked material is then broken up and ground and may be screened to remove the large: articles. When this material, consist-l articles to ing' o varying sizes from line small lumps, is used'in an electrical fuse, it

' is found that there is a tendency f or the material -to pack and quite often in]ury to the.

fuse element is caused during shipment. Even if it is attempted to screen out particles or lumps of a uniform size, the particles readily break up into iner particles and the sametroubles occur.

It' is :1 -purpose ofthe present invention to provide an. improved method of manu; facturing the fuse powder so as to produce granules or pellets of material of substair' t1 ally uniform size and which will not readily disintegrate.

It is further an object of the invention to providea method whereby the final productcan be obtained'in one stage of treatment without subsequent screening.

It is an object of the invention to introduce the powdered calcium sulphate in a tumbler barrel and to spray water into the tumbler barrel so that the calcium sulphate takes up a certain percentage of water andtends to form granulesor pellets as the barrel is rotated. and to continuousl screen the inateriel as it is being mixe .with the water so as to remove the particles orgranules of desired size as they are formed.

Further objects and advantages of my 11nproved method will be more readily a parent PL substantially uniform particlesize.

final vproduct will not settle -or'cake from vthe following description ta en in connection with the attached drawing-,in

' .As shown in the daw'ing,stheiappareitusiis of'simple' construction: and-#may :consistvof `is supported .by'rsliaft l2I and fdrivenfrfrom cur. 13; -J The :barrel 11 is `closed? at 'th-deft, and -endeandscurved'lliftinghlades`15 are.;

the other end of the barrel. The fscreen may fahebarrerbyithe ena-ingenieurs fans 'aperue the screen 17 and the particles-of thepr'oper size which do not pass through the screen varefdirected into a. receptacle 21'. I

The base material which is used plaster 'paris or calcium sulphatebut in addition, '-75 water. A's the particles of calcium sulphat-80 i unite with the water, lthey are continuously rolled over each other and mechanicall unite "tot form the larger particles. TheA ifting t blades 15 carry the material to thetopof'tlie barrel whereby it is 'deposited on the.'scieerfil8 5l 17. The mesh of the screen 17 determines Y" the size of the' particles desired'. The parti# cles which are not yet of the propervsize 'fall i through'and are again subjected to the tum4 bling action to :form particles of ler er'sizel i' vtion of the tumbler maybe Vcontinued all the material has been deposited in the receptacle andthe. final product will have a` Although the emi product is especiauymf'-l.,

suitable for use as va filler in an electrical fuse, it will be obvious that a method such as I have described will be applicable to other uses in which a powdered material is united with n. 5 fluid so as to form granules or pellets.

Iclaim: y y 1;.. .The method fof: treating material which is capable of setting with water so as to form `pellets which consist in adding the Water tc 10 'the material While it i's'heng'l-'slibjectedto a* tumbliiig action :and simultaneously scree1iing the material as it is tumbled to remove pellets of the desired size. j"

2. The method cfg-manufacturing.fuse 15 powder which consists in charging a pov(lerecl base-material capable of: setting-withf';

water into a tumbling barrel', sprayingw'aterfupQntliemat'erial Whilethe barrelSis rotated jan clv simultaneosly screening ltlie iixe'd'mate: tmi rial while itl-is'fbeing subjectedtothegaction 'ofthe tumbling barrel-so as to remove pellets .ofthe'desiredsizeas soon as they are foimjed.'.; 3: The metho'd.. of m'anfacturin'g 'a fuse. ..po.irderv -Which vconsists '.insiibjecting Aa- 'pow-'- 25 =clered massofcalcium sulphate to v.atuligbling action,"spraying Water upon-.the powdered" .mass'while itis being tumbled, and conti.- nouslj/iscreen'ing the tuinbli1ig-mass solas to remove vpellets ofthe desired 'size fror the -3Q tumbling action" substantially asiastas `tl1e=` pellets areformed. 

